The water Chiller with cooling capacity of 1231kW installed and in use at Fábrica Carioca de Catalisadores S.A. has been analysed and is modelled forward simulating in the platform UNISIM. This study has the main objective of modelling and validating the real model based on comparison with measured parameter for steady state conditions. Based on the validate model, it is expected to be able to evaluate modifications of thermal load therefore obtain the refrigerating effect per power input.